Endoscopy has become an increasingly important tool in diagnosing and in treating ailments of the gastrointestinal tract, also referred to as the GI tract. Typical endoscopes are essentially formed by a somewhat flexible tube that is pushed through the GI tract, after being introduced in the body cavity starting from the rectum or starting from the esophagus. The endoscope has a steerable tip to facilitate navigation through the GI tract, and typically has to be sufficiently stiff so that it can be pushed further along the body cavity. The tip of the endoscope that is introduced in the GI tract can be outfitted with several devices, most notably an illumination device and a vision device, such as a vision integrated circuit, so that the operator of the endoscope can observe the interior of the GI tract and maneuver the endoscope in the proper position.
Once the endoscope is in position, other tools attached to the endoscope or inserted through the endoscope can be brought to the proper position in the GI tract. Various procedures can then be carried out, such as removing polyps, performing sutures, irrigation, suction, and removing other tissues. The various tools that are used together with the endoscope can be either inserted separately in the GI tract and placed in the proper position independently, or may travel in a working channel of the endoscope, so that once the endoscope is positioned at the desired location in the GI tract, the tools inserted in the endoscope will also easily reach that position.
Endoscopes or other smaller similar devices can also be used to explore other body cavities, for example airways, genitourinary tract, female reproductive organs, etc., or blood vessels. These probes must be small to fit in the smaller cavities, and care must be taken to avoid damage to the more fragile membranes lining these cavities.
Current state of the art endoscopes are very capable devices, and endoscopy has been very successful in diagnostic and therapeutic applications with the use of current endoscopes and the current arsenal of tools that can be inserted through the working channel of the endoscope, or can be attached to the outside of the endoscope. However, current endoscope technology has limitations and drawbacks. One of the greatest drawbacks of current endoscopes is that the working channel is small. The working channel is small relative to overall diameter of the endoscope, and is further limited by the space taken up by vision, irrigation, suction, light, and control cabling mechanisms that are part of the endoscope and are required to control the endoscope. Thus there is a very small area left for other tools to be introduced through the endoscope. Also, the additional channels may make passage of the endoscope through body cavities more difficult, as they contribute among other things to its diameter.
U.S. Pat. No. 6,517,477 to Wendlandt, assigned to Scimed Life Systems, Inc. (Maple Grove, Minn., US), which is incorporated herein by reference, describes a catheter introducer system for endoscopy that includes a steering section and a propulsion section located near the end of the flexible, tubular catheter that is introduced in a body cavity. The propulsion section is designed to pull the rest of the catheter inside the body cavity, so there is no need to push the catheter along from outside the body. Propulsion may be accomplished by relatively movable gripping pads that selectively apply suction to the tissue. The steering section is designed to point the end of the catheter that is introduced into the body cavity in the desired direction. The catheter may be made very flexible in bending, and a larger diameter catheter may be used.
U.S. Pat. No. 6,800,056 to Tartaglia et al., which is incorporated herein by reference, describes an endoscope with guiding apparatus. A steerable endoscope is described having an elongate body with a manually or selectively steerable distal portion, an automatically controlled portion, a flexible and passively manipulated proximal portion, and an externally controlled and manipulatable tracking rod or guide. The tracking rod or guide is positioned within a guide channel within the endoscope and slides relative to the endoscope. When the guide is in a flexible state, it can conform to a curve or path defined by the steerable distal portion and the automatically controlled portion. The guide can then be selectively rigidized to assume that curve or path. Once set, the endoscope can be advanced over the rigidized guide in a monorail or “piggy-back” fashion so that the flexible proximal portion follows the curve held by the guide until the endoscope reaches a next point of curvature within a body lumen.
US Patent Application Publication 2004/0199087 to Swain et al., which is incorporated herein by reference, describes a method for inserting guide wires into a lumen, for example into the human gastrointestinal tract. A guide wire structure is employed which comprises at least two guide wires each having a leading end portion which terminates in a leading end, the guide wires being connected to one another by a junction at or adjacent their leading ends, the guide wires have a first position in which the leading end portions are substantially parallel to one another, a second position in which the leading end portions are curved, and a third position in which at least one of the leading end portions forms a loop. The guide wire structure is steered through the gastrointestinal tract by selectively advancing or retracting a single guide wire or advancing more than one guide wire simultaneously, according to the path which is required to be followed.
US Patent Application Publication 2004/0199088 to Bakos et al., which is incorporated herein by reference, describes a guide wire including a continuous, unitary wire having a first segment, a second segment, and a third segment. The third segment has a bending moment of inertia less than the bending moment of inertia of the first and second segments. The guide wire is described as being used to advance a medical device within a body lumen.
PCT Patent Publication WO 2004/010858 to Gross et al., which is incorporated herein by reference, describes an imaging system comprising an imaging device assembled on a carrier, and a first outwardly expandable element and a second outwardly expandable element mounted on the carrier, wherein the second expandable element is expandable both radially and axially, the imaging system comprising a mode of operation, wherein during expansion of the second expandable element, obstruction of the radial expansion of the second expandable element causes the axial expansion of the second expandable element to propel the carrier and the imaging device axially.
PCT Publication WO 99/40957 to Blume et al., which is incorporated herein by reference, describes a guide wire combined with a catheter or medical device for moving through a body lumen to a desired position in the body with the aid of an applied magnetic field. The guide wire is provided with a magnet on its distal end that is oriented or oriented and moved by the application of a magnetic field to the magnet. A catheter or other medical device is advanced over the guide wire. Once the medical device is in its desired position, the magnet may be withdrawn through the lumen of the catheter.
U.S. Pat. No. 6,837,846 to Jaffe et al., which is incorporated herein by reference, describes an endoscope that is slidably insertable within a lumen of a guide tube. The guide tube is configured to be rigidizable along its entire length from a relaxed configuration. The endoscope has a steerable distal portion to facilitate the steering of the device through tortuous paths. In the relaxed configuration, a portion of the guide tube is able to assume the shape or curve defined by the controllable distal portion of the endoscope. Having assumed the shape or curve of the endoscope, the guide tube may be rigidized by the physician or surgeon to maintain that shape or curve while the endoscope is advanced distally through the tortuous path without having to place any undue pressure against the tissue walls.
U.S. Pat. No. 6,827,718 to Hutchins et al., which is incorporated herein by reference, describes a steerable endoscope that uses rapid exchange technology, soft locks, and mechanical locks to maintain the position of the endoscope. Rapid exchange technology is used to minimize displacement forces present on the guidewire or catheters. Soft locks and mechanical locks are described as resisting movements caused by displacement forces.
U.S. Pat. No. 6,786,864 to Matsuura et al., which is incorporated herein by reference, describes an endoscope including a fixing member detachably mounted to a distal end portion of an endoscope insertion part for detachably fixing and holding a distal end portion of an indwelling tube or a distal end portion of a guide member for guiding the indwelling tube, both of which are provided along the axial direction of the insertion part, to the distal end portion of the insertion part.
U.S. Pat. No. 6,695,771 to Takada, which is incorporated herein by reference, describes a self-propelled colonoscope that is self-inserted into a colon by driving endless belts mounted on the outside of a bending section of an insertion tube. The cross section of the endless belt is substantially circular, and rack gear teeth having a circular cross section are formed on the outside of the endless belts.
U.S. Pat. No. 6,764,441 to Chiel et al., which is incorporated herein by reference, describes a self-propelled endoscope including expandable actuators surrounding a central conduit. Each actuator comprises a bladder that, when fluid is introduced, expands laterally while contracting longitudinally. A restorative spring can be placed inside a bladder and between the two ends to restore the actuator to its original shape as fluid is withdrawn. Multiple actuators can be placed in series to successively inflate and deflate and generate a peristaltic motion. One or more Shape Memory Alloy (SMA) springs can be affixed to one or more restorative springs to cause bending motion.
U.S. Pat. No. 6,702,734 to Kim et al., which is incorporated herein by reference, describes a self-propelled endoscopic micro-robot that is propelled through a tubular organ in forward and backward directions by an impact force generated within the robot by a propulsion piston that is moved within a cylinder of the robot by an alternating source of pressurized air.
US Patent Application 2004/0199087 to Swain et al., which is incorporated herein by reference, describes a guide wire structure that comprises at least two guide wires each having a leading end portion which terminates in a leading end, the guide wires being connected to one another by a junction at or adjacent their leading ends, the guide wires have a first position in which the leading end portions are substantially parallel to one another, a second position in which the leading end portions are curved, and a third position in which at least one of the leading end portions forms a loop. The guide wire structure is steered through the gastrointestinal tract by selectively advancing or retracting a single guide wire or advancing more than one guide wire simultaneously, according to the path which is required to be followed.
The following patent application publications, all of which are incorporated herein by reference, may be of interest:
US Patent Applications 2003/0225433 and 2003/0074015 to Nakao
US Patent Application 2004/0199196 to Ravo
US Patent Application 2004/0260150 to Bernstein
US Patent Application 2004/0204702 to Ziegler et al.